The White House on Monday reiterated that President Barack Obama would not negotiate with Republicans over the threat of a debt default, sticking to its line as stock prices fell and the U.S. government shutdown moves into its second week. The initial problem of the US government shutdown stemming from Republicans refusal to fund the government for the current fiscal year due to contention over healthcare reform has now merged into the issue of raising the debt ceiling as its upcoming decision date in Congress looms over the uncertainty of the U.S.’ economy. Republican House Speaker John Boehner vowed on Sunday not to raise the U.S. debt ceiling without a “serious conversation” about what is driving the debt, while Democrats said it was irresponsible and reckless to raise the possibility of a U.S. default.